This invention relates to a magnetic recording medium, and more specifically to such a medium which combines an improved still reproduction property with good resistance to wear on repeated running past heads.
One of the essential characteristics required of the magnetic recording medium is the still property. If satisfactory still reproduction is to be ensured in playing back television signals by a video tape recorder, the wear of the magnetic tape surface due to the drawing of the tape past the heads must be avoided. During the still reproduction, for example, one existing system scans an arcuately formed tape portion near a rotating head with two magnetic heads which are mounted 180 deg. apart on a rotating drum and are revolved at a high speed. If the tape is not wear-resistant, the tape surface will be gradually scraped out, resulting in a shorter still reproduction time.
In order to improve the still reproduction property, it has been customary to incorporate a nonmagnetic powder harder than Cr.sub.2 O.sub.3, Al.sub.2 O.sub.3 or other magnetic powder into the coating layer of the tape. As is known in the art, this improves the wear resistance of the tape but that of the heads has to be seriously sacrificed. After all, this type of magnetic recording medium is required to meet the two contradictory requirements, i.e., improved still reproduction property due to increased wear resistance of the tape and reduced wear of the heads. To achieve the dual end, it is necessary to take steps to minimize the head wear and improve the still property.